最上川流域におけるイバラトミヨPungitius pungitius(LINNAEUS)の分布と変異 : 特に鱗板上の変異について
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概要
- 論文の詳細を見る
In Japan, some five species of sticklebacks have been described. Bodily characters were studied in some of them in full detail by Ikeda (1950), Kobayashi (1957), Ishigaki (1967) and Nelson (1968), because of their biogeological significance in ralation to evolution. The writer studied the distribution of Pungitius pungitius occurring in the Mogami basin, and found a striking difference in the development of scutes by living places. The specimens living in Yusa, the upper part of the river, and in Shinjo, and Takinohira located in the middle part, had scutes in the shoulder region and also in the caudal pedancle. It is apparent that the fish of the above localities are of the normal semiarmata type. These living in Tendo had scutes which cover from the shoulder region to the caudal pedancle. They are noted as the lateral scutes of trachura type. These fish thus look like Pungitius sinensis. But, except those in the caudal pedancle, the scutes show a striking tendency of degenration. Ikeda (1933) described these fish as being a special type of Pungitius pungitius. It seems that this type-splitting found in Pungitius pungitius from the Mogami basin can be explained as two different types of neoteny. Probably, the scutes of the Tendo fish develop much further than those of the others. The neotenization of the former seems to take place at a later stage of life than that of the latter. On this basis the writer assumes that the above-mentioned two types of the fish were landlocked at considerably different times, and that each had pursued its own evolutionary course, adapting itself to its own environment.
- 社団法人日本動物学会の論文
- 1969-09-15
著者
関連論文
- 最上川流域におけるイバラトミヨPungitius pungitius(LINNAEUS)の分布と変異 : 特に鱗板上の変異について
- 福井県産トミヨPungitius sinensis(Guichenoi)